Keep in mind that this is an amplifier only, with no volume control or onboard surround processing (though it does offer independent adjustable output controls for each channel). It's designed for use with a stereo preamplifier or a surround receiver offering preamplifier outputs.
Making the move from 5.1- to 6.1- or 7.1-channel surround sound? If your receiver has preamp outputs for all channels, there's no need to replace your 5.1 surround receiver. Just feed the additional center or surround signals to a strategically positioned Amp 200. Read more AudioSource AMP-200.